Windows XP SP2 Firewall causing Security Log to fill

Hey all,
I just wanted to ask if anyone else has had this happen.
XP SP2 was installed a few days ago, and now there is an error showing up on
the log on screen that the security log is full and has to be cleared by the
administrator.
The Event ID is listed as a security event and id is 861.
The Windows Firewall has detected an application listening for incoming
traffic.
Here are the details on it.

Name: -
Path: C:\WINDOWS\system32\lsass.exe
Process identifier: 1276
User account: SYSTEM
User domain: NT AUTHORITY
Service: Yes
RPC server: No
IP version: IPv4
IP protocol: UDP
Port number: 1106
Allowed: No
User notified: No


I know that I can just set the firewall to allow this program but what is it
and why does it need access out, and if it is important why did it not
automaticly receive access out.
Thanks guys and gals.